16 Nov
2012
16 Nov
'12
2:40 a.m.
On Thu, 15 Nov 2012, Andreas Abel wrote:
Sounds ok, by why especially for Set. Why not (also)
Map.intersectionList :: Ord k => Map k a -> [k] -> Map k a Map.differenceList :: Ord k => Map k a -> [k] -> Map k a
? Screams for a generalization.
I assume that Map.differenceSet can make use of the internal tree structure of a set and is thus more efficient. The documentation of Map.difference says it uses an adaption of hedge-union and this could also be used for Map.differenceSet.
This is true for Map and Set, although the difference versus Map.insersection m (fromSet (const ()) s) will be probably minor. It is not the case for IntMap and IntSet, as these has different representation. Cheers, Milan